In particular moving blades and guide blades of compressor stages and turbine stages of aircraft engines must be checked during production and/or maintenance. Inter alia, the profile shape is checked on the suction side and/or pressure side of the blades. In particular, their leading edges and/or trailing edges are checked as to whether the actual radii are in a predefined tolerance range.
This has previously been carried out according to internal practice, by registering an actual contour of the particular blade and ascertaining a minimum inscribed circle of curvature for this contour automatically and comparing its radius to a setpoint edge radius. For this purpose, FIG. 2 schematically shows as an example a part of a blade cross section having an actual contour 1 and a setpoint edge radius rtot. Due to a small local deviation of the actual contour from a setpoint contour, the inscribed circle of curvature having minimal radius of curvature rlok is ascertained therein and compared as the edge radius to setpoint edge radius rtot. As a result, as is recognizable in the example, actual profile 1 is classified as flawed in the automatic evaluation due to the large deviation between minimal radius of curvature rlok and setpoint edge radius rtot, which requires an additional manual check by trained personnel. Since in the example actual contour 1 corresponds sufficiently with a setpoint contour, which is described in the area of the leading edge by setpoint edge radius rtot, the blade is accepted therein. Accordingly, the previously known automatic check by ascertainment of and comparison to minimal inscribed circles of curvature results in erroneous objections and therefore in substantial additional effort due to the manual check by trained personnel.